Microsoft released updated version of the app two days earlier for Windows Phones, but it was never approved by Google. There was supposed to be an approval from Google because both companies were working on App for Windows Phone. There were uncertain errors on the app and Google has confirmed that they are blocking the new app. Google representative mentioned in a statement that every developer have to follow our Terms of Service and app was violating TOS.
Microsoft said that they are working with Google to solve all the issues. Microsoft should have worked to know that app does not meet the requirements. If it violates the TOS why it was launched before confirming? You cannot blame Microsoft for the issue because Google is not interested in developing an app for Windows Phone users due to less number of users. Google will not work on the app until there are more Windows Phone users and it is very strange stance by the giant. Some of the people said that Google is trying to hurt Windows Phone reputation.
Microsoft is to be blamed for having slow development on Windows Phone OS. Google is guiding Microsoft in developing the Youtube app for Windows. However, MS has to show good faith and efforts to meet the requirements before making it available for the users.